From: "trans.  (T. Onoma)" <transami@...>
Date: 2004-10-02T01:13:29+09:00
Subject: Re: ruby-dev summary 24298-24353

On Friday 01 October 2004 03:50 am, Robert Klemme wrote:
> class Adaptor
>   def initialize(obj, mappings)
>     @obj = obj
>     scl = class<<self; self end
>
>     # delegation of all public methods
>     obj.public_methods.each do |m|
>       m = m.to_sym
>
>       unless mappings[m]
>         scl.class_eval { define_method(m) { |*a| @obj.send(m,*a) } }
>       end
>     end
>
>     # remapping
>     mappings.each do |m,mapped|
>       case mapped
>         when Symbol
>           scl.class_eval { define_method(m) {|*a| @obj.send(mapped,*a) } }
>         when Proc
>           scl.class_eval { define_method(m,&mapped) }
>         else
>           raise ArgumentError, "Must be Proc or Symbol"
>       end
>     end
>   end
> end
>
> With this we can do
>
> >> sample = %w{aa bb cc}
>
> => ["aa", "bb", "cc"]
>
> >> fake_class = Adaptor.new(sample, :new => :dup, :=== => :==)
>
> => ["aa", "bb", "cc"]
>
> >> x = fake_class.new
>
> => ["aa", "bb", "cc"]
>
> >> "Is an instance of? #{fake_class === x}"
>
> => "Is an instance of? true"
>
> >> x.id == sample.id
>
> => false

Let me see if I understand this correctly. This is essentially a quick way to 
create an adapter class based on a preexisting object. Is that right, or is 
there more to it?

Also, what are you using this for? It seems cool enough, but I'm trying to get 
a fix on it's uses.

T.